Bitfenix Unveils The Whisper PSU Line

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Vatharian

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Four 12V rails? Thank you, I'll pass. I'll get it, times when cross-loading lines would blow up fuses is gone (I had PSU that needed 100W resistors on unused 12V rails or else would shut down at 8A difference), but come on, that's wasting power!
 

turkey3_scratch

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I think you have some misconceptions of how multi-rail PSUs work.
 

Vatharian

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I understand them perfectly, I was making a comment in view of history of PSUs, when regulations forced max 20 A per rail, resulting in 6-rail 1200W monsters.

Multi-rail PSUs have advantage of isolating devices from each other (so you can run noisy fans/pump and delicate soundcard or some exotic interface that requires stable ripple-free power source from one PSU, but the cost is you have to carefully balance current on different rails, and if you don't have right number of devices, you'll end up wasting power - you won't be able to use full current capacity of power supply. Efficiency will also suffer, since it's unlikely you'll be able to balance the rails for that sweet 75%. Single-rail has advantage of giving you always your max current capacity regardless of number of connected devices, at the cost of small crosstalk, but they are usually much higher quality. Some PSUs use multiple bridged rails, which is possibly worst choice - you have (usually) lower quality components, you have crosstalk, and small imperfections will create current flow between regulating circuitry of each rail, that will hurt service time and efficiency.
 

turkey3_scratch

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No no no no. A multi-rail unit can easily be turned into a single-rail unit just by shorting the shunts that go to the protection IC. The protection IC is the only thing that differs, what wires are linked to what overcurrent protections; overcurrent protections which kick in far after the rated amperage of said rail. You don't need to do any manual distribution, what cables go to what protections are already built into the design.

It has no effect on efficiency. All the wires from these "rails" all come from the same source, the same 12V rectifiers, they're filtered by the same capacitors. Just some of those wires are separated into their own little protections so in the situation of an overload from a short that SCP does not detect the unit will shut off before you have melted wire at the bottom of your case.

Multi-rail costs more money to implement than single-rail (and stuff that's worse never costs more money). This is because multi-rail is safer, there is no denying that. But of course the some companies chose a better route: use the cheaper, less-safe single rail and turn it into a marketing point. Now we have XFX's "Easy Rail Plus" or some crap like that. And the American market bought this stuff like crazy, so much that spending more money for multirail is almost pointless since 90% of people do not realize it's a safety measure and nobody will buy their multi-rail power supplies based on false myths from sly marketing gimmicks.
 

NightLight

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what does alarm me, is the poor solder quality shown in the picture. If you look at the blue tantalum in the right upper corner, there's almost no solder between the top pin and the board. Same for numerous points I can see.
 

emgarf

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If they can't even spell "performance" correctly, they can't be trusted to design electronics.
 

memadmax

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Looks like a decent build. If there were caps on the lines that go to the GPU card(s) not just the main one going to the mobo then I would be more interested in this box.
 

Valantar

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...because in 99% of cases, they aren't visible? And their job is to deliver high quality power, not look good? A box is a box, regardless of the decor. Also, stickers are removable. I agree that the logo is bad, but so what?



"We have already evaluated two members of this line, and the results were good."

Where is the review?
 

iam2thecrowe

Glorious
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Each 12v rail on the 450w model its own on can produce 25A, that's 300w.......
Can't think of a reason why you would pull more than 300w from a single rail on a 450w unit?
 


This may be true about most units, but staying inside spec is the safest way to go in case one particular model won't do 35A on one rail, or most of the units in a model will but some barely-test-passing units might shut you down.
 

randomizer

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I wish my previous PSU followed the +10A rule. It wouldn't have smelled so bad.
 

Onus

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No. If it is a multi-rail PSU, there is almost always some amount of "cushion" in the OCP set points, assuming OCP is properly configured, however 10A is unlikely. Consider also that OCP could also be missing (e.g. some Coolermaster units), even if it is claimed.
If it is a single-rail PSU, even if [falsely] advertised as multi-rail, this will almost certainly not be true, unless it's a really good, overbuilt unit (unlikely on smaller models that a mere 300W +12V rail suggests).
Sorry, Turkey, this was particularly poor "advice." We know you know better. Being wrong on this one could mean a smoked PSU.
 

turkey3_scratch

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No Onus. Look at any recent Tomshardware review where OCP is tested. It usually kicks in around 130℅. I feel there are too many misconceptions about multiple rails.

Most single rail PSUs lie about having OCP and only have OPP (think Seasonic with the S12ii)

The whole purpose is that the protections kick on before smoke so no what I'm not saying is not stupid.
 

Onus

Titan
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Claimed protections may be missing. PSUs claiming multiple rails may be single-rail with a liar-label. As cheap as some builders can be with their PSUs, there is absolutely no certainty they will have a PSU that is accurately labeled and has properly configured OCP setpoints. You could be right, but you may not be, and where you are not, damage is possible. I've read PLENTY of PSU reviews at HardwareSecrets, HardOCP, or even JG, where there was a problem with OCP. It may not be a problem with the "better" units, but too often that's not what people buy. That is the context in which your answer needs to be considered. Your statement may well be true for all of the units that "we" (e.g. members of the Moderation team; other knowledgeable users) buy, but will often NOT be true for people coming here for help.
 

turkey3_scratch

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I wasn't giving anybody advise. All I made was a statement of truth - and I used the term "usually" because I do think carefully about what I say.

@Randomizer: so you bought a budget PSU and overloaded it? Why?

My concern was to address the numerous statements I see about "This PSU is rated for x amps on this rail so x amps is the max it can provide" - that's just not a true statement.
 
Technically, you are correct. Many PSUs will give you more than the rated power on a given rail.

Practically, system builders should stay within spec unless they have proper testing equipment to ensure that the specific unit in hand will handle the extra load on the rail, without degrading power quality. It's a safety issue. Another reason for breaking up a single high-power 12v source into several OCP-limited 12v sources is to prevent pushing more current through a wire than the wire can handle. Power supplies keep getting bigger, but the wiring standards don't move up with them. With a single rail, a PS could push enough current into a single cable to seriously damage the cable. Yes, system builders can work around that by distributing the load sensibly, but breaking it up provides extra safety.

So both sides are correct in their own context.
 

turkey3_scratch

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Very few people overload their power supplies, though. The majority of people get overkill power supplies (with some exceptions, looking at you Randomizer). The main concern is when there is a short. Short circuit protection only works for shorts where the impedance is less than 0.1. There are some shorts that make the PSU simply think "this piece of hardware is demanding more power" and it'll just jack up the power until the cable melts, versus on a multi-rail unit there's a better chance of OCP kicking and preventing the wire from melting or something else getting damaged.



You took what I said out of context. I was saying that usually if something is rated for 25A it can do a lot more. This is shown in numerous reviews where they overload the PSU (really only Hardwareinsights and present day Toms and TPU do it). Somehow you said this was poor advise...

Really though, in my opinion, if a unit doesn't have any overcurrent protection, it should be denoted as having 0 rails rather than 1.
 

Onus

Titan
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No, I said that only in certain contexts (which could be a majority) was your statement about OCP and exceeding specs accurate. In other contexts, it can be dangerously inaccurate, to the point that the context should be specified to avoid potential for damage. The companies that apply liar-labels (e.g. Apevia, Diablotek, Logisys, Coolermaster) are not held accountable for their deceit, therefor it should always be mentioned, rather than making a potentially hazardous generalization. Usually may be true, but it can be very important to specify when it is not, to avoid risk, even if the reader misinterprets what was said. "That guy on TH said this would be fine, so why is smoke coming out of my PSU!?? Dammit!"
 
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